Fernando Alonso believes any one of ten drivers from the top five teams could win the Australian Grand Prix this weekend.

The stability in regulations from 2012 to 2013 has led to predictions that the grid will be even more closely matched this season and the times from pre-season testing indicate that is likely to be the case. As a result, Alonso believes that Ferrari, Red Bull, McLaren, Lotus and Mercedes will have an advantage over the rest of the field but that any driver from those teams has a chance of winning the season-opening race.

"It's difficult to know; no-one knows who can win this race at the moment," Alonso said. "We'll have to wait and see to answer some questions that winter testing doesn't answer. I think there are top teams with a little bit of advantage, maybe it's not the same as last year when we saw seven different winners from seven different races, it was a bit mixed on the grid.

"I think this year with the consistency in the rules I expect the five top teams to have a little advantage and to have many, many surprises in the first races. From these five teams I think it's very difficult to see really after winter testing who has this extra two or three tenths that can make you win. At the moment I think it's very close and very difficult to choose one favourite.

Asked if that meant he thought any one of ten drivers could win the race, Alonso replied: "I think so.

"I think Mercedes, McLaren, Ferrari, Lotus and Red Bull showed some potential in different days in testing and in different parts of races last year and I think it's difficult to choose."

Focusing on the progress made at Ferrari, Alonso admitted he is much more confident heading in to the new season than he was 12 months ago.

"It was not difficult to start better than last year because it was difficult to start any worse. We were a little bit too far behind and the winter has been much better than last year with understanding the car and working with the car and getting the results that we more or less expect. That gives us much more confidence and optimism to start the season with."